Method and apparatus for producing artificial thread



Dec. 6, 1938. A G. M. KARNS 2,139,449

METHOD AND APPARATUS FOR PRODUCING ARTIFICIAL THREAD Fil ed June 3, 1956 4 Sheets-Sheet 1 IN VEN TOR.

- I v George gums Fm. 2; ,,-,A,

ATTORNEY.

- Dec. 6, 1938. G. M. KARNs 2,139,449

METHOD AND APPARATUS FOR PRODUCING ARTIFICIAL THREAD Filed June 3, 1956 4 Sheets-Sheet 2 INVENTOR. George H. urns ATTORNEY FIG. 1 1

Dec. 6, 1938. G. M. KARNS 2,139,449

METHOD AND APPARATUS FOR PRODUCING ARTIFICIAL THREAD Filed June 5, 1936 4 Sheets-Sheet 5 INVENTOR. Georye 11.Karns WLA/ ATTORNEY.

Dec. 1938- G. M. KARNS 2,139,449

METHOD AND APPARATUS FOR PRODUCING ARTIFICIAL THREAD Filed June 5, 1936 4 Sheets-Sheet 4 IN VEN TOR.

m H2 H6 ,Geo ge llfams A TTORNEYI Patent ed Dec. 6, 1938 UNITED STATES METHOD AND APPARATUS Fon'. PRODUCING 'rmm ARTIFICIAL George M. Karns, Kenmore, N. Y., assignor, by mesne assignments, to E. I. du Pont de Nemours & Company, Wilmin of Delaware gton, Del., a corporation Application June 3, 1936, Serial No. 83,323

14 Claims.

Jhis invention relates to the-manufacture of continuous filament thread and more particularly it relates to a process of simultaneously spinning, tensioning and also preferably winding a plurality of continuous filament, artificial silk threads by the use of unitary tensioning and winding apparatus. In its specific aspects, the invention has particular utility in the production of fine denier artificial silkthread.

The invention will be oescribed'with particu-. lar reference to the manufacture of regenerated cellulose thread from viscose, however the invention is equally applicable to the production of all kinds and types of continuous filament artificial silk threads which are subjected to tension during the spinning thereof.

The production of continuous filament threads having uniform high tenacity, uniform elongation anduniform good affinity for dye stuffs in volves the use of considerable equipment 'for each thread during its passage between the spinneret through which the spinning solution is extruded and the bobbin on which the freshly formed thread is collected. This is particularly true in apparatus provided with roller guides or the like, which will impart a stretch to a freshly formed thread without any substantial sliding friction. Each thread, 'in such case, will be provided with its individual series of roller guides and a bath tank of large area in which each thread requires its own area ofbath travel. Furthermore, each thread must be provided with its individual guiding mechanism for traversing the thread as it is being wound onto the collecting bobbin.

as to 50 denier, and having "a comparatively high tenacity, such as 2.5 grams per denier or greater, has many desirable characteristics which render it admirably suitable for certain uses, for example, for the production of transparent velvet and sheer underwear. Continuous filament fine denier thread having a suitably high tenacity v inafter.

Consequently, the poundage of thread produced with -comparatively expensive equipment is extremely low. Furthermore, the use of a. plurality terial degradation thereof.

Continuous filament thread of fine denier, such.

of roller guides to provide the desired long bath travel results in imparting-too much tension to the threads. Threads of 100 denier or more are not subjected to nearly so high a tension in grams per denier as are fine denier threads (25 to 50 denier) under similar conditionbecause the load is distributed over larger or a larger number of filaments. Therefore, it has been necessary, heretofore, to pass fine denier threads about a smaller number of roller guides and to materially reduce length of-bath travel to prevent ma- In either case the thread produced will be of inferior quality.

It has now been found that high quality, fine denier threads can be produced by passing a plurality of threads about a single series of roller guides whereby to cause said threads to collectively propel said series of roller guides thus to collectively share the burden and benefits presented by the process. The burden of turning the rollers is uniformly distributed among the several threads and a long bath travel is threads.

It is therefore an object of the present invention to provide a method of increasing the production of artificial silk thread.

It is another object of this invention to provide a method for increasing the production and preventing the over-tensioning of hightenacity fine denier artificial silk thread.

It .is another object of this invention to provide means for the production of a plurality of .possible without over-tensioning any ofthe artificial silk threads on unitarytens'iom'ng and winding apparatus.

It is a still further object of this invention to provide means for the production of a plurality of high tenacity fine denier artificial silk threads on unitary tensioning and winding apparatus whereby to distribute the tension imparted by the apparatus jointly on the several threads.

Other objects of the invention will appear here- The objects of the invention may be accom 'plished, in general, by simultaneously passing a plurality of freshly formed, partially set threads, particularly fine denier threads, as they issue from one or more spinnerets, around a single series of roller guides, and simultaneously winding said threads on one or more collecting bobbins.

In accordance with the preferred embodiment of the invention the production of high tenacity fine denier threads comprises passing each of a plurality of fine denier threads about individual, separated grooves of a single series of roller guides. In this manner the tension on the threads is borne collectively by the several threads, and consequently it is possible to pass the fine denier threads over the desired length of bath travel and about any desired number of roller guides without danger of placing an excess tension thereon.

The features of the invention and the benefits to be derived therefrom will be more clearly apparent by reference to the following detailed description taken in connection'with the accompanying drawings, illustrating several specific embodiments of the invention.

In the drawings:

Figure 1 is a diagrammatic plan view of a spinning and winding apparatus constructed and arranged in accordance with the invention.

Figure 2 is a side elevational view of the apparatus shown in Figure 1.

Figure 3 is an enlarged plan view of a collecting bobbin and the manner in which a plurality of threads would theoretically be wound thereabout.

Figure 3A is a plan view of a bobbin showing the manner in which the threads actually will be wound at the ends thereof.

Figure 4 is an enlarged elevational view showing a roller guide of the type suitable for use in the present invention.

Figure 5 is an enlarged view of a modified form of roller guide.

Figure 6 is a top plan view showing a modified form of winding apparatus suitable for use in the present invention.

Figure 7 is a modified form of spinning nozzle and thread guide arrangement suitable for use in the present invention.

Figure 8' is a side elevationalview of a modified form of apparatus.

Figure 9 is a diagrammatic plan view of the apparatus shown in Figure 8.

Referring to the drawings reference numeral Ii designates a supply conduit of a cellulosic solution, such as viscose, and which is connected to metering pump I3. The pump I3 forces the cellulosic solution through header conduit I5 and branch conduits l1, l9 and 2|. The branch conduits l1, l9 and 2| are provided with downwardly extending conduit lines 23,25 and 21 so that the ends thereof may be submerged below the surface of the coagulating bath 59 in the tank 53. Each of the downwardly extending conduits 23, 25 and 21 are provided with spinnerets 29,

3| and "respectively. The cellulosic solution is.

extruded through the spinnerets to form threads 35, 31 and 39. The threads 35, 31 and 39 are guided by means of stationary guides ll, 43 and 45 respectively to the first of a series of roller guides 31. The roller guides are all provided with a plurality of circumferential grooves 53, 5| and 49 (see Figure 4). The individual threads are passed about the single series of roller guides 41, four of which are shown in Figure 1, each of which roller guides is provided with a separate groove for each thread-so that the individual threads may be-maintained separate from the other threads throughout their travel in the coagulating both, and the tension under which thethreads are placed by the guides in evenly divided among the several threads. In this manner a plurality of threads are coagulated and tensioned in a bath tank of small area-in which the various threads are spaced vertically from eachother in the same bath area. From the last roller guide 41 the threads are passed ,over individual roller guides 5|. The individual roller guides 6|, see Figure 2, are spaced from each other in such a manner that the threads 35, 31 and 39 are spaced from each other a considerable distance at the points where they leave the said guides iii. The individual thread guides 6! are positioned on stub-shafts connected to a frame 63 which is fixedly connected in any desired manner to the tank 58. The spaced threads 35, 31 and 39, as viewed from Figure 2, converge at a point a: where they contact the collecting bobbin 61. A reciprocating thread guide 55 is positioned at an angle 1 to the thread so that the length of the individual threads from the reciprocating guide 65 to the bobbin 51 will be unequal in length.

Inasmuch as the length of the individual threads, 35, 31 and 39, between the reciprocating thread guide 65 and the bobbin 61 are unequal in length, the individual threads will contact the guide 65 at spaced points from each other and will be laid on the bobbin in parallel helixes which are spaced from each other a distance a which is determined by the difference in length of each thread between the guide 65 and the bobbin 51 and the angle of the helix. The reciprocating thread guide 55 is composed of two legs 51 and 59, between which the threads are positioned. Leg 69 of the guide 65 will contact and guide the individual threads when the guide is traversing in the direction of the arrow shown in Figures 3, whereas leg 61 of the guide will contact the thread when the guide is being traversed in the opposite direction. Referring again to Figure,1 of the drawings, when the guide 85 is travelling to the right as shown by' the arrow the threads will be'laid on the bobbin in parallel helixes until they reach the position shown by the dotted line on the right hand side of the bobbin. At this position of the individual threads 35, 31 and 39 the traversing guide 65 will be reversed to travel in the opposite direction and the individual threads will naturally and inherently cross themselves, since the thread which defines the shortest distance between the guide 65 and the bobbin 61 will again lead the other two threads, 31 and 39, when the three threads are being laid on the bobbin, and the traversing guide 65 is moving, in a direction opposite to the arrow. Figure 3 shows the theoretical lay down of the threads if the reversal of the traverse guide were instantaneous and if the guide also moved the distance B instantaneously at the time of reversal. It is to be noted that thread 35 leads in both directions and at the time of reversal crosses threads 31 and 39 as shown. In actual practice, however, there is a small fraction of a second when the guide 65 reverses its motion and moves back from position C to position D which necessitates shortening the stroke somewhat from that shown by position C in Figure 3. Consequently the threads will be laid down as shown in Figure 3A so that the threads are parallel and superimposed for a short portion of their length.

By this arrangement, though the threads run separated and in phase during the greater portion of the cake or while the rate of thread travel along the bobbin is essentially the same as the rate of travel of the traverse guide, the threads are out of phase with one another when the rate of travel of the traverse guide slows down and reverses atthe end of the traverse stroke at first approaching one another, then crossing one another and finally separating once more, the thread with the shorterenrollment radius leadmg in both directions "as has heretofore been 15 that could be uniformly treated, the threads lie,

together and behave as a single thread. Thus by means of a single traverse guide a plurality of yarns may be wound as a single cake of excellent formation which permits easy and uniform washing and other liquid treatment of the yarns on the bobbin and permits the several yarns to be subsequently unwound from the bobbin without difilculty. The angle u (see Figure 2) which the guide 65 makes with the threads is important in enabling me to keep the threads separated one from the other in the major portion of the cake and although'this separation is no more than it is suflicient' to effect easy unwinding of the individual threads.

I The bobbin 61 may be rotatably positioned in any desired manner such as, for example, by stationary arms 69, and may be driven by any desired known mechanism, such. as, for example, pulley II. v

Each of the roller thread guides provided with any desired number of the accommodation of threads. provided with vanes 55 for the purpose of imparting a slightly increased resistance to the rotation of the roller guides and thereby supplymay be grooves for two, three, four or more ing to the threads an even tension, substantially free from sliding friction, which is gradually increased from roller guide to roller guide as the thread-is being traversed through the coagulating bath. The advantages and benefits to be derived from the use of vanes on roller guides comprises the subject matter of application No. 303,574, filed September 1, 1928, by W. H. Bradshaw et al.

Although the above described arrangement is one of the preferred means and methods for carrying outthe applicant's invention, various ,modificationsiof this apparatus and procedure may be used with very beneficial results. It may, for example, be desired to use a single spinneret of large size for the forming of the threads in the coagulating bath and the filaments issuing from ,the large spinnerets may be dividedand passed over stationary guides and to a single series of roller guides in the manner illustrated in Figures 1 and 2 of the drawings. Such a modified form of apparatus is partially illustrated in Figure '7 in which the cellulosic solution is passed from the supply conduit II through thepump "to conduits I5 and I6 and forced through the spinneret I8 from whence the invidlual filaments are divided and passed about the stationary guides ll, 43 and 45, and are thence passed to the first thread guide 41. a

It may furthermore be undesirable to wind all three threads on a single bobbin as illustrated in Figures 1 and 2 of the applicant's drawings. In

such .case the threads as they 'pass from the individual roller guides 6| are led by means of stationary or roller guides I5, 11, I9 and 8|, see Figure6, to individual traverse guides 83, 85, and 81, respectively, to be wound on individual collecting bobbins 89,3I and 93. The traverse guides in this case may be connected to reciprocate in unison with each other, and the various bobbins 89, 9| and 93 may, if desired, be driven' by a single shaft. Alternatively "the threads maybe wound on a large beam in the manner above described or on individual sections of the beam.

. The individual threads, may, for example, be

These roller guides may furthermore be maintained separated from each other over one or two rollers having the necessary number of individual separating grooves, and may then if desired be converged and carried together over successive rollers and subsequently separated by the individual roller guides 6l andthe traverse guide in the manner shown in Figures 1 and 2 of the drawings.

It 'may in some cases be desired to .preserve the individual filaments of the thread in closer contact with each other so as to prevent any entanglement of the filaments of the thread with the mechanism. It may, therefore, be of advantage to position the roller guides 41 at slight angles to the vertical whereby to impart a temporary twist to the thread due to the rolling action of the bundle of filaments on the surface of the individual roller grooves; Alternate twists to the left and to the rightcan be imparted to the threads by passing the same about a roller guide which will oscillate allowing the yarn first to ride on one bevel ofthe V-shaped groove and then on the other. 'I'hismay be accomplished, for example, by the use of a roller guide as illustrated in Figure 5 of the drawings. In this case the grooves 95 and 96 of the roller guide IOI are cut with an irregular curvilinear outline of a rather deep axial pitch to cause the individual threads to be oscillated in the manner above described. These roller guides may, if desired, also be provided with vanes '55 for the'purpose above set forth.

. By using 3, 4, 5 or more rollers in the bath for each group of threads a very long bath travel and a gradual application of a relatively high spinning tension can be secured while spinning 2,

or 3, or more threads instead of the customary single thread spun in the. same space. Thus, it is not only possible to spin an increased number of fine denier threads on a single spinning machine,

travel of 50, '70 or even 100 inches may be used to produce a yarn having a dry tenacity of 3 grams per denier or more, an elongation of over 10% and which has a uniform afiinity for'a direct dye stuff.

Figures 8 and 9 illustrate a very desirable modified form of apparatus in which the spinning solution is passed from conduit III to branch conduits H2, H3 and I I4, then through individual metering pumps H5, H6 and Ill and is extrudedthrough spinnerets IIB, I I9 and I to form threads I2I, I22 and I23 respectively. The several threads are passed around the stationary guide I25 and rotatable roller guides I21, I29, I3I, I33 and I35. Each of the roller guides is provided with a single circumferential groove, as shown in Figure 8, although if desired roller I35 may be replaced by a plurality of rollers such as rollers Si in Figure 2, whereby the threads l2l,

I22 and I23 are coag'ulated and tensioned while in close contact with eachother. From the roller guide I35 the threads are passed over a separating comb I31, which maintains the threads separated from each other. The comb I3! is pref-' eraby connected with the traverse guide I33 to be reciprocated in unison therewith. This may" beachievedyfor example, by fastenlng both the parallel helixes.

angle to the threads whereby to wind them onto bobbin 3 in substantially parallel helixes as above described with reference to Figures 1, 2 and 3 of the drawings. In positioning the three threads about the apparatus shown in Figures 8 and 9, the individual threads or groups of filaments extruded from each spinneret are kept separated to the extent that they may be individually passed through the comb I31 and thus to be maintained separated from each other when they contact the traverse guide I39. Since the several threads or bundles of filaments are not twisted together but are maintained in parallel relationship while on the roller guides they will be easily and continuously separated by comb I31. If desired, the several spinnerets H8, H9 and I may be rotated at a comparatively slow speed to place a slight twist in the individual threads, thus to prevent any possible entanglement of the filaments of one of the threads with those of another.

Figures 10 and 11 designate another modified form of traverse guide which is adapted to separate the threads and lay them onto the bobbin in In this form of device the traverse bar I 5i is provided with a plurality of spaced I53. threads will be passed between respective adjacent sets of guides I53 which will function simultaneously as a separating comb and traverse guide means to maintain the threads separating guides The individual separated from each other and guide them onto the bobbin in spaced helixes.

By means of this invention I am able to spin simultaneously 2, 3, 4, 5 or more threads in a coagulating bath having substantially the same surface area as has heretofore been required to spin a single thread. This is an extremely desirable feature since a rayon spinning plant may now produce as much yarn of any denier as the capacity of the plant for making viscose permits. In other words there is no longer the necessity of running the viscose manufacturing plant at half capacity when the size of yarn is reduced from 150 denier to denier, for now in the same bath area that was needed to produce one thread I can produce several threads without any additional investment in expensive equipment. For instance, by any of the usual prior art methods a regenerated cellulose thread of normal strength, i, e. 1.7 g/d dry strength can be produced witha bath travel of from 10 to 20 inches and a single tensioning guide which spinning arrangement will require about 75 square inches of surface bath area. Following my invention I can produce simultaneously 2, 3, 4, 5 or more threads of substantially the same character, each of the several threads being spun with the same bath travel, same tension and same thread speed and all of the threads in substantially the same surface area of the bath as the prior art thread.-

In the case of regenerated cellulose thread having a dry tenacity of at least 2.5 grams per denier where a bath travel of more than inches is required and where a total spinning tension of at least 0.5 g./d. isimposed by means of a plurality of roller guides, a much larger surface area of bath is required being about 200 square inches. Here again by means of my invention I am'able to produce 2, 3, 4, 5 or more threads of substantially the same character as the single prior art thread referred to whether it be 25, 50, '75, 100 or still larger denier in size and spin all the threads in substantially the same surface'area of the bath as the prior art thread or in an area more grams per denier of about 200 square inches. In previously known spinning methods, the spinning of 2, 3, 4, 5 or more threads would therefore necessitate a bath area of 2, 3, 4, 5 or more times the 200 square inches above referred to.

Thus it is possible to spin a plurality such as 2, 3, 4, 5 or more 50 denier threads at a thread speed of at least 3000 inches per minute, a bath travel of 100 to inches, 9. bath temperature of 45 C. and a spinning tension of 0.5, 0.7 or even in an area of 150 to 250 square inches which area was previously required to spin a single 50 denier thread of substantially the same physical properties.

Yarn produced in the manner above set forth has uniform physical properties and is at least as free from broken filaments, fluff, and the like as is yarn of this type processed according to the usual method. If it is desired to produce yarn of different physical properties, this can be accomplished by increasing or decreasing the numsame manner as bobbins of yarn produced in accordance with previously known methods. If the yarn is to be twisted it may be desirable to merely wash the yarn on the bobbins and to carry out further purification of the yarn subsequently to the twisting thereof. As a further alternative, yarn produced in accordance with this invention may be washed and purified and, prior to drying, unrolled from the bobbin, drawn through a sizing bath then through a drying zone and finally wound on a spool or cone. The size sticks the filaments together and makes it unnecessary to twist the yarn. By drying the sized yarn on the run under very little or no tension it will have a low and uniform residual shrinkage characteristic.

When the yarn is to be twisted, it may be dried on the bobbin, or if desired, it may be twisted directly from the wet cake, for example, by passor around a dryer roll. In either case, the bobbin of yarn is preferably placed on a roll-of! device and the individual threads carried through separate guides around feed rolls and thence to separate spools on a ring twister or the like. The yarn will unwind without difilculty'when wound in the manner above-described and the plurality of threads can be twisted from the single bobbin as easily and quickly as could the same length of yarn be twisted from two separate bobbins under the same twisting conditions, i. e.,spindle speed, feed roll speed, etc.

Although the invention has particular utility .in the production of high tenacity, fine denier yarn in view of its possibility of providing a long bath travel with a long nd gradual increase of tension on fine denier thread by causing the fine denier threads to jointly bear the burden of tension produced by each individual roller guide, nevertheless. a very important broad advantage of the invention is the increased production of a spinning machine. Therefore the invention in its broad aspects includes the spinning of threads of large denier as well as fine denier.

Since it is obvious that various changes and "while maintaining them in spaced relation to each other, and winding said plurality of threads in parallel spaced helixes to form a single thread package.

2. The process of simultaneously winding a plurality of threads on a single collecting bobbin to form a single thread package which comprises passing said threads toward said bobbin while maintaining the same separated from each other, positioning a traverse guide insuch a manner as to continuously contact said threads at an angle to the direction of thread travel so that the lengths of the several threads between said guide and bobbin are unequal, and reciprocating said traverse guide during the rotation of said bobbin.

3. In an artificial thread producing apparatus, means for simultaneously forming a plurality of threads, a plurality of rotatable thread. tensioning means, each of said thread tensioning means constructed and positioned to contact each of said threads, while maintaining the latter in spaced relation to each other, in such a manner as to simultaneously place tension of substantially equal amount per thread denier on all of said threads. v

4. In an artificial thread producing apparatus, means for simultaneously forming a plurality of threads, a plurality of rotatable thread tensioning guides, a plurality of grooves on each guide, said guides positioned relative to each other in such a manner that each of said threads will contact a separate individual groove of each of said g'uideswhereby to simultaneously place a tension 'of substantially equal amount per thread denier on all of said threads.

5. In an artificial thread tensioning mechanism, a plurality of rotatable thread tensioning guides, each of said guides having spaced means for individually contacting one of a plurality of threads, said guides positioned relative to each other in such a manner that said plurality of threads can be separatedly maintained in contact with each of said guides to simultaneously place a tension of substantially equal amount per thread denier on all of said threads.

6. In an artiflcialthread tensioning mechanism, a plurality of roller thread tensioning guides, each of said guides having spaced means for individually contacting one of a plurality of threads, said guides positioned relative to each other in such a manner that a plurality of threads can be separatedly maintained in contact with each of said guides to simultaneously place a tension of substantially equal amount per thread denier on all of said threads, said guides constructed and arranged to be rotated by said threads. i

7. In an artificial thread producing apparatus,

means for simultaneously forming a plurality of threads, a plurality of rotatable thread tensioning guides, said guides positioned relative to each other in such a manner that the several threads will contact each of said guides, whereby to simultaneously place a tension of substantially equal amount per thread denier on all of said threads. means for guiding said threads at angles to each other toward a collecting bobbin, a thread bobbin, said'traverse guide positioned to contact said threads at an angle to their direction of travel in such a manner that the length of the thread between the traverse guide and the bobbin is unequal, means for reciprocating saidtraverse guide, and means for rotating said bobbin.

8. In a thread winding mechanism, a thread collecting bobbin, a traverse guide, means for passing simultaneously a plurality of threads at angles to each other through said guide toward said bobbin, said traverse angle to the direction of travel of said threads so that the lengths of the threads between the traverse guide and the bobbin are unequal, means for reciprocating said traverse guide, and means for rotating said bobbin.

9. In an artificial thread producing apparatus, means for simultaneously spinning a plurality of threads, a coagulating bath, a plurality of thread driven rotatable guiding and tensioning means insaid bath, each of said means being positioned to guide and tension each of said threads whereby the tension placed on the threads by the means is collectively borne by said plurality of threads.

10. In an artificial thread producing apparatus, means for simultaneously spinning a plurality of threads, a coagulating bath, a plurality of thread driven rotatable guiding and tensioning means in said bath, each of said means being positioned to guide. and tension each of said threads while maintaining said threads separated from each other, whereby the tension placed' on the threads by the means is collectively borne by said plurality of threads.

11. In an artificial thread producing apparatus,

.means for simultaneously spinning a plurality'of on each means, said means being positioned relati ve to each other in such a manner that each of said threads will contact a separate individual groove of each of said means whereby the tension placed on the threads by the means is collectively borne by said plm'ality of threads.

12. The process of producing flne denier, artificial threads which comprises simultaneously passing a plurality of freshly spun threads substantially in parallel vertically spaced relationship to each other through acoagulating bath whereby to increase the number of threads pro-. duced. in a coagulating bath of a given surface area.

13. The process of producing fine denier, artificial threads which comprises simultaneously passing a plurality of freshly spun threadsback and forth substantially in parallel vertically spaced relationship to each other through a coagulating bath, whereby-to-increase the number of threads produced in'a coagulating bath of a given surface area.

14. The process of producing iin'e denier,

pack e.

as GEORGE 1!. ms.

guide positioned at an traverse guide for traversing said threads on said artificial threads which comprises simultaneously passing a plurality of freshly spun threads in 

